The invention relates to a waterproof, water vapor permeable shoe construction including an exterior upper, a waterproof, water vapor permeable functional-layer upper, a lining upper, and a sole, as well as to a method for manufacturing a waterproof shoe.
Shoe constructions of this type are well known. For example, U.S. Pat. No. Re 34,890 describes a shoe construction having an exterior upper and a sock-shaped lining, with the lining consisting of a three-layer laminate. This laminate is used to make the shoe structure waterproof and water vapor permeable and typically contains a functional layer giving the laminate a waterproof, water vapor permeable property and other layers of other material, such as textile layers.
The manufacture of waterproof, water vapor permeable shoe constructions using laminates is very complex, because production of the three-dimensional shoe form from two-dimensional laminates can be done only by cutting them into shaped pieces and then joining the pieces, preferably by sewing, after which the joints, the seams in the case of sewing, must then be sealed in order to restore the waterproof quality of the three-dimensional structure produced in this manner.
In the embodiment known from U.S. Pat. No. Re 34,890, a sock-shaped, three-dimensional structure is formed from the laminate, the structure then being inserted into the exterior upper. This sock-shaped, three-dimensional structure can be produced from the two-dimensional laminate only by using multiple seams. Each individual seam must then be sealed in order to render the sock-shaped, three-dimensional structure waterproof.
A laminate can be produced, for example, by gluing together the individual layers that are to form the laminate, such as a first functional layer and at least one second layer. The functional layer is waterproof and water vapor impermeable, while the remaining layers, which normally are textile fabrics such as woven or knitted fabrics, are water vapor permeable but not waterproof. If the various layers are now glued together over their entire surface, the full-surface adhesive hinders the water vapor permeability of the functional layer, so that the finished laminate has reduced water vapor permeability compared to the functional layer. For this reason, such laminates are frequently produced by joining the individual layers at distributed points. However, with this method the number of gluing points is still high enough that a reduction of the water vapor permeability of the laminate compared to the functional layer alone is noted in this case as well.
It is often difficult to ensure the tightness of the required seams, even if the seams are sealed afterwards, because each seam and also the threads of the textile fabric can transport water into the interior via capillary action. Moreover, it must be ensured that the sealing material penetrates the textile fabric up to the functional layer, since the joints of the shaped functional-layer pieces, which are arranged behind the textile fabric as seen from the sealing side, must be sealed, and this is not always completely successful. Furthermore, the strain involved when the shoe construction is worn can loosen the seam seal, so that the waterproof quality cannot be guaranteed at these locations.
In the aforementioned methods of manufacturing waterproof, water vapor permeable shoe constructions, it is also necessary to form from the laminate a three-dimensional structure adapted to each respective shoe size. This also increases production costs.
A further problem is that the constructions used up to now to manufacture waterproof, water vapor permeable shoes are different from the shoe constructions used for other shoes. The resulting variety of designs makes mass production very expensive.
The object of the present invention is to provide a shoe construction as initially described, in which the aforementioned problems are at least reduced.
The object is achieved with a waterproof, water vapor permeable shoe construction including an exterior upper, a waterproof, water vapor permeable functional-layer upper, a lining upper, and a sole, in that both the waterproof, water vapor permeable functional-layer upper and lining upper are sock-shaped and inserted separately into the shoe.
According to the invention, the term xe2x80x9cinserted separatelyxe2x80x9d means that the functional-layer upper and lining upper are produced separately in manufacturing the shoe construction of the invention and not combined until the shoe construction of the invention is manufactured. The functional layer and lining are thus not combined as a laminate to form an upper. This characteristic is also clearly observable from the completed shoe construction.
If the functional-layer upper is sewn together from shaped pieces, it is evident that the seam is arranged only in and on the functional layer. The lining upper can be produced by form knitting, for example, and in this case has no seams. If the lining upper is like-wise sewn together from shaped pieces, these seams are joined only to the material of the lining upper. There is thus no single seam that joins both the shaped pieces of the lining upper and those of the functional-layer upper.
In the case of seamless functional-layer uppers, it is also clearly observable that the functional-layer upper and lining upper were previously separate, since, even when the two uppers have been joined together, it is evident that the joining of the two uppers can only have been accomplished after producing them separately.
The separate insertion of the functional-layer upper and lining upper into the exterior upper also allows simple use of the construction designed for manufacturing waterproof, water vapor permeable shoes to make other shoes unrelated to the invention, by omitting the functional-layer upper during production. In this way, the type variety on the part of the shoe manufacturers can be reduced considerably.
The shoe construction of the invention can be produced especially economically if the functional-layer upper and lining upper are joined to the exterior upper only at a top opening of the shoe construction through which a foot is inserted. As a result, the shoe structure of the invention is considerably easier to repair. Since the functional-layer upper and lining upper are joined to the exterior upper only at the top opening, the functional-layer upper and lining upper can be withdrawn from the interior of the shoe before repairs are undertaken on the remainder of the shoe structure, without endangering the functional-layer upper, which is generally sensitive and thin. The functional-layer upper can also be replaced easily if its waterproof quality is impaired, since only a single joint with the exterior upper must be renewed.
For the joining at the top opening, it is especially practical to fold the exterior upper over the functional-layer upper and lining upper at the upper opening, in order to form the joint between the functional-layer and lining uppers.